On 10/26/2021 2:11 PM, André G. Isaak wrote:
> Anyone who has studied math or logic will have a far better grasp of
> philosophy than you do. I have no idea where you get the idea that
> people in these fields are ignorant of the relevant philsophy.
>
> And 'self-evident truth' isn't a notion that has played a significant
> role in philosophy in at least the last century and a half. It's an
> antiquated notion and it doesn't even remotely approximate 'theorem'.
>
There you go, your only understanding of philosophy is learned-by-rote.
Because you and all other logicians and mathematicians really only have
learned-by-rote as your basis you have no deep philosophical
understanding that self-evident truth provides the ultimate foundation
of all analytical knowledge.
> But the main point is that whatever you want to call this it isn't
> actually the criterion which is specified by the problem at hand. If you
> want to address the halting problem, you need to use the same criterion
> as that problem.
>
>> a general proposition not self-evident but proved by a chain of
>> reasoning; a truth established by means of accepted truths.
>>
>> In epistemology (theory of knowledge), a self-evident proposition is a
>> proposition that is known to be true by understanding its meaning
>> without proof.
https://en.wikipedia.org/wiki/Self-evidence
>
> A notion dating back to the Ancient Greeks which has proven to be
> entirely inadequate. Euclid considered his fifth postulate to be
> self-evident[*]. But no one today would accept it as such.
>
>>
>>>> Whenever simulating halt decider H correctly determines that input P
>>>> never reaches its final state (whether or not its simulation of P is
>>>> aborted) then H correctly decides that P never halts.
>>>>
>>>> q0 ⟨Ĥ⟩ ⊢* Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥqn
>>>
>>>> As soon as I show that Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ meets the above theorem then Linz
>>>> has been refuted. Only a fool would disagree.
>>>
>>> Things don't 'meet a theorem'. That's gibberish. They satisfy a
>>> criterion. And in the case of Linz's H/Ĥ the criterion is ALREADY
>>> STATED as part of the problem (though you keep deleting it).
>>>
>>> Linz CLEARLY states the criterion:
>>>
>>> q0 ⟨Ĥ⟩ ⊢* Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ ⊢* Ĥqn IFF Ĥ APPLIED TO ⟨Ĥ⟩ HALTS.
>>>
>>
>> If Linz says this then Linz is wrong. A halt decider is correct iff it
>> correctly decides the halt status of it inputs.
>
> A halt decider decides the halting status of the *computation*
> represented by its input. Which is exactly what Linz states. The input
> itself is just a string. It has no halting status.
>
>> The halt decider is at Ĥq0 it is not at q0.
>> The inputs to the halt decider at Ĥq0 are: ⟨Ĥ⟩ ⟨Ĥ⟩.
>
> Neither Ĥ nor Ĥq0 are halt deciders at all.
>
Linz says that Ĥq0 is the "no" path of H.
If you want to get freaking nit picky it is a non-halting determiner.
>> As long as Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ correctly determines that its inputs never
>> reach their final state then Ĥq0 is necessarily correct and impossibly
>> incorrect.
>
> The inputs don't have final states.
>> As long as Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ correctly determines that
THE SIMULATION OF
>> its inputs never
>> reach their final state then Ĥq0 is necessarily correct and
>> impossibly
>> incorrect.
> The machine they represent does. And
> its about that machine applied to the supplied input string that a halt
> decider is expect to decide. That's a simple matter of definition.
>
If for whatever reason the behavior of Ĥ applied to ⟨Ĥ⟩ does not match
the correct halt status of the input to Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ it cannot possibly
show that this correct halt status is incorrect.
As long as Ĥq0 ⟨Ĥ⟩ ⟨Ĥ⟩ applies correct axioms to the behavior of the
simulation of its input such that it correctly determines that this
simulation of this input would never reach its final state whether or
not Ĥq0 aborts this simulation, then Ĥ is necessarily correct when it
transitions to Ĥn no matter what the behavior of Ĥ applied to ⟨Ĥ⟩ is.
> André
>
> [*] Or at least he presented it as such, though there are reasons to
> believe he wasn't overly satisfied with this and would rather have
> derived this from the first four postulates, but this proved impossible.
> Of course, he's dead, so we can't really ask him about this.